1998 Chevrolet Camaro Refrigerant

Hi I was wondering if it is illegal for me to vent R134a. I want to remove the condenser for my 1998 Z28 Chevy Camaro. I want to remove the camshaft because one of my valve lifters have went. Before I change just the lifters I want to make sure that the camshaft is ok. This is the only way I know how to do this without pulling the motor out which I don't want to do. I wouldn't think venting R134a is illegal just because it is sold on the market and it is a HFC. Their is no chlorine in it to hurt the ozone. Plus this car leaks refrigerant so I might as well change the seals out in it while it is empty. My next question is how hard is it to set the valve lash on the LS1 motor. I have seen how it is done but I am just curious. Since I am replacing the lifters should I take the heads off and change the seals. I know this is a rolling camshaft. I believe they call it a rolling camshaft I think. Also if I put a competition cam in it I was told you have to change something on the transmission I don't remember what it was though. Thanks.